Oral Contraceptives: Risks and Benefits

Since first introduced in the 1960s, the birth control pill ("the pill") has been a popular and extremely effective form of contraception. The pill is easy to use and, when taken correctly, it is 95% to 99.9% successful at preventing pregnancy. But, as with any medicine, there are both risks and benefits.

What Are the Risks of Taking the Pill?

Unintended Pregnancy

While birth control pills are highly reliable in preventing pregnancy, there is the possibility that you could become pregnant. This is especially true if you miss a dose or do not take the pills regularly.
Being overweight
or obese may also increase your risk of pregancy. The excess weight may affect how well the pills work in your body.

Blood Clots

Oral contraceptive pills can increase your risk of developing blood clots in the veins in your legs. These can become life threatening if the blood clots leave your legs and travel into you lungs. The risk of blood clots is increased more in people who smoke.

Cholesterol Levels

There are different kinds of birth control pills. Some are combination pills, with estrogen and progestin, while others are "mini-pills" with just progestin. Estrogen may affect triglyceride levels and total cholesterol levels—increasing HDL "good" cholesterol and decreasing LDL "bad" cholesterol. Progestin, though, may cause "good" cholesterol to lower and "bad" cholestorol to rise. But, for most women, these changes in blood levels are not strong enough to have a poor effect on your health.

High Blood Pressure

Taking birth control pills may increase the risk of
high blood pressure
. This risk may be greater if you have other conditions, like being overweight, having a family history of high blood pressure, or
smoking
. If you take birth control pills, your doctor will check your blood pressure. If you already have high blood pressure, talk to your doctor about other contraceptive options.

Cardiovascular Disease

Women aged 35 or older who smoke heavily and take birth control pills have an increased risk of having a
heart attack
or
stroke
. You may have an even greater risk if you have other risk factors (eg, family history of cardiovascular disease,
high cholesterol
, high blood pressure). If you want to take birth control pills, you should first
quit smoking
, since smoking increases your chance of developing many other health problems.

Cancer

Taking birth control pills for many years may increase the risk of certain types of cancer, like
cervical cancer. Researchers are still investigating the link between birth control pills and
breast cancer. Some studies have found that there is an increased risk, while others studies have come to the opposite conclusion. According to the National Cancer Institute, there appears to be a slight increase in risk, but the risk level goes back to normal after 10 years of stopping birth control pills. It is important to remember that there are many other risk factors for cancer. If you are at high risk for breast cancer (eg, having certain types of genes or a family history) or other types of cancer, talk to you doctor about the best contraceptive for you.

What Are the Benefits of Taking the Pill?

Cancer

While the pill may increase the risk of some types of cancer, it can also decrease the risk of other types of cancer, like
ovarian
and
endometrial cancer
. Studies have found that the more years a woman takes the pill, the better her protection. In addition, researchers are investigating whether birth control pills decrease the chance of developing
colorectal cancer.

There are many different types of birth control pills on the market. You and your doctor can decide which kind is best for you, or if a different contraceptive option would be a better choice. Just keep in mind that the pill does not protect against
HIV
and other
sexually transmitted diseases
.

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

SOGC position statement: the birth control pill and cancer. The Society of Obstetricians and Gynaecologists of Canada website. Available at:
http://www.sogc.org/media/guidelines-oc%5Fe.asp. Updated February 19, 2008. Accessed June 26, 2012.